Actually you did have that conversation but I was too ignorant to know what it really meant.....I do appreciate your trying to help me..... I must correct you here though....... Dave did not catch it... I did....... after a conversation with Don from DMH when he asked me what size the ports were for a possible Stahl header evaluation...... I looked at the Megan when it came off was surprised ..... showed it to Dave and Dave started "whittling away"

To Msfitoy's point .....no one has made a point of this in any thread that I have read...... and all you guys who know this stuff with the exception on K-Huevo never brought it to light ..... as well Randy Webb himself never brought it up and I bought the head and header from him ...... WTF,,,.... I wonder how many heads and headers are matched... I can tell you that it makes a hell of a difference......

My car does have matched intake manifold

The Mlltek is on the car and I'm loving it...now that it is matched..... it may not be the best and the collecter is suspect but the noise level is acceptable and I am happy with the power and performance......



BTW.... thank you Don

 

I was talking with my brothers (the neon boys) about port matching the exhaust to the header. They're no pros, but they surprisingly advised against it to some degree. Their valid (atleast got me thinking) point was that the exiting gases needed to tumble a bit to more efficiently evacuate the chamber and that a stepup in the header was actually beneficial. To what degree...? SpiderX was a whole square inch restricted, maybe the ideal is somewhere between matched and that square inch.... ? Then again, maybe smooth is the path.....

 

There seems to be a consensus that you want to maximize exhaust gas velocity.... If the exhaust gas velocity theory is valid, then anything that slows it down will not be good.... Things such as miss-matched exhaust header - port size come to mind as something that slows the exit of the exhaust gases....

 

I can tell you that with the ports matched vs what I had there is a very noticeable difference in every aspect

ex.the acceration at half throttle is the smoothest it has ever been...... this is a nice bonus....

Don and Dave are both proponents of zero restriction.....

 

zero restriction to the exiting gasses, but a positive restriction to the reverse flow is desireable. done by making the header flange opening slightly larger then the port opening on the head.

Interesting about the capabilitiesWegner shop; what exactly do they have? Larry has state of the art valve grinding, head surfacing, block boring and honing and 5 axis CNC port machining abiliies plus an engine dyno and laminar flow flow bench. for what it's worth, CNC the ports and Cchambers first then you still finish up by hand. I don't think Larry has cam or crank grinding machines.

 

--From what I can tell the Stahl header/cat back is the only performance exhaust system built for the Mini. If there are others I have not ever seen them.
--I am sure Endyne has excellent equipment and such. I was only commenting on the differing level of resources and technology available. Cosworth is the only company you can compare Wegner to. The next level up in America is proprietary NASCAR race shops. (Read about Wegner and the race teams that use their engines and you’ll get the idea.) And if you do not think NASCAR is pretty much at the top of the food chain in resources/technology then you are not aware of the budgets employed by the top teams. It is a staggering figure.
--If you are looking for performance and can afford it, why not take advantage of the opportunity of a Wegner head and Stahl exhaust?

 

With the kind of mods I see on this board & the $$$$ spent, not to mention future mod expence......... Hey the mods for the Mini far exceede the cost of big time mods for a SB Chevy. In fact an easy read is "Hot to hot rod the SB Chevy"... lots of tricks.

There are 100s of books on subjects relating to almost every question posted here on NAM. Answers for some of these questions are not a clear black or white, this is where differing philosophys are formed. That said, K-huevo just posted the best advice.... almost as important as "get the manual before you mod the car".

 

for those interested Msfitoy has a thread on "here we go again" about his response to my conversation with him and he has posted a picture tthat is almost exactly what I saw in my car... someone who knows how can bring the picture into this thread.....

 

Here ya go Bob...

 

By the way..that is the Megan style.....

Thanks Sid

 

I just took a precise template from the head itself to double check the first template taken from the gasket...

 

This discussion makes me believe that many past disappointing aftermarket header installation results have been the result of poor matching of exhaust port-to-gasket-to-header flange, rather than header design flaws or "needing" an expensive aftermarket head, valve and cam in order to realize gains from a header.

If so, then some who added aftermarket headers and were disappointed by the results might find some added horses for a small price by simply removing their headers, checking the match-ups in their assemblies, and removing any "excess" materials from their flanges (and/or gaskets, as appropriate).

Do any of you think it is likely that significant improvements could be made without even removing and modifying the head itself? (that is, by just making certain that the header installation properly matches and "steps" the port-to-gasket-to-flange openings?

Obviously, the potential for substantial gains is not as great as it is for head work, but this approach to header installation could definitely improve the "bang-for-the-buck" that one could gain from JUST a header install, no matter what brand of header it might be.

Heck, maybe even blueprinting the OEM header gasket and flange could be worthwhile for those who can't afford aftermarket hardware at this time?

 

I am certain that matching is beneficial..... I recommend doing it after my experience but if you have a head with enlarged exhaust ports and your header is not opened up... from my experience you have wasted your money...... only MSFITOY knows the disappoinment I felt about the WMS head becasue he has one as well and was not happy with it as an upgrade....we both felt it was not much, if any bang for the buck..... by simply matching the header..... my opinion has changed...... I finally feel like I am getting what I paid for..... I guess Randy thought I would know better but I did not.....and it was never made clear or explained.....as i already stated K-Huevo tried to tell me about this but I really did not get it...... i have learned alot about this engine in the last year.....in the last 3 mo for that matter..... MSFITOY is in the process and I am interested in his impressions

 

you never, i mean NEVER, want a blockage to flow like the mis-match shown in the header photos above. Like JLM said, anti-reversion steps can provide benefit. Tumble in exhaust gasses is BS, it's on the intake side it's relevant, but for mixing, not flow...

Matt

 

You don't want to disturb the momentum.... for any reason. The port configuration determines the laminar flow, in & out. It could be that there is too much tumble on the stock Mini that is a part of the "flat spot" causing the exhaust gas to rise in temp.

 

This discussion makes me want to check my header now. Anyway I have a new question. I just read the all the posts to this thread from the beginning and noticed that most people driving there cars want the most power in the Mid RPM range. How much of a difference would it make if you improved your top end performance or higher RPM's. I drive my mini on the street and regularly find myself at 7,000 rpm. By the way I am in Italy and have driven on the autobahn and autostrasses over here. I am a very spirited driver and on the autobahn have torn it up with a few high end cars. Anyway would it be more benificial for me to just have a head worked for topend or would that really ruin my low end grunt considerable?

 

Follow this thread too as I'm in the middle of this subject...

https://www.northamericanmotoring.co...=1#post1189470

 

For that person who inquired about the stock header. One of the many advantages of the stock header is the way the primaries are fitted within a recess in the header flange. The weld is away from the end of the primary pipe so material can be removed from the flange as well as the inside lip of the primary without compromising the integrity of the bond. The step-down at the bottom is substantial enough to retain its important anti-reversion function after the flange port is opened up. For a stock header & head combo the flange port wouldn’t need alteration unless the primary is welded off-center. The stock header pictured has been port matched to an ENDYN head. Nothing had to be removed from the stock header gasket.

 

One down...three to go...

 

Uh, ENDYN (no E) started working with NASCAR over 30 years ago. Over 20 years ago, they pioneered the use of CAD/CAM technologies in chamber and port finishing manufacturing techniques. They haven't stagnated. Not saying you guys aren't capable, its just that sometimes budget is not the only measure of effectiveness.

http://www.theoldone.com/about/default.asp

 

Edit: Nevermind, moved to different thread.

 

I am more than aware of whom they are; I lived in Dallas in the early to mid '80s and utilized some of their parts. However, I am speaking of today rather than 10 years ago and the money today is with Wegner.
Technology in racing changes fast; just look at the differing port designs of Endyn, Wegner, and Cosworth. On top of that comes the valve work and that is where 3/4 of head work money goes.
I truly have no interest in arguing the minutia because I think people buy what they want no matter what the reality is.

 

Books WTF are they


Good points

 

I think those are the thingies that they have in the library

 

How's vacation?